1. Field of the Invention
The present invention concerns a hearing aid of the type having a movable contact element which can be operated with a battery pack
2. Description of the Prior Art
Due to the development of more powerful rechargeable battery pack power supplies, it is possible to equip and to operate hearing devices with such a battery pack. A problem that results is that the battery pack must be recharged at periodic intervals, which typically occurs in a charging device. For this purpose, the battery pack typically must be removed from the device and be placed in the charging device. Since hearing devices, in particular in-the-ear (ItE) hearing devices, are quite small, it is difficult to remove the battery pack from the device. This is particularly true for older hearing device wearers. Hearing devices were therefore developed which exhibit a permanently installed battery pack. To allow the battery pack in the hearing device to be charged, it is known to design the battery pack so that it can be charged by induction. For example, such a hearing device with battery pack that can be charged via induction is described in U.S. Pat. No. 6,498,455.
A battery pack that can be charged by induction is complicated in terms of design and requires additional space (which is always tightly allocated in a hearing device). The charging by induction also requires a complicated charging device and a high energy consumption.
EP 0630 549 B1 discloses a hearing device with chargeable battery pack wherein the device housing has openings through which the charging pins of a charging device can contact the charging contacts of the battery pack. The charging pins of the charging device protrude into the openings in the hearing device housing upon charging. This has the disadvantage that dirt can get into the openings during usage of the hearing device. This can lead to a contamination of the charging contacts, which can make further charging procedures more difficult.